Sponsored Content
The Lounge What is on Your Mind? Popularity-Boost for the POSIX-Shell in the Era of Containerized Computing? Post 303028311 by stomp on Friday 4th of January 2019 08:17:28 AM
Old 01-04-2019
Popularity-Boost for the POSIX-Shell in the Era of Containerized Computing?

Not even thinking that POSIX-Shell is deprecated, but I like working with bash very much, because of it's increased comfort and advanced functions. And in my world here it's available everywhere as default.

Working with kubernetes now, it seems there is a paradigm shift in terms of resources. Small is beautiful is one old and new slogan here. Faster to backup, Faster to set up, Less I/O. A popular linux distribution for containers is alpine linux: Default Installed Image size: ~5 MB. Based on busybox and musl.

With kubernetes(or with other container technology) you can use resources far more effectively and that's why small resource footprint gains you really much in terms of how many applications can I run on the cluster?

Want to install bash? Nearly Triples space usage of that whole system. So size really matters...

Debian/Ubuntu docker base images are at 80-120 MB with my final app images(small apps) around 200-400 MB.
 

9 More Discussions You Might Find Interesting

1. Virtualization and Cloud Computing

Event Cloud Computing - IBM Turning Data Centers Into ?Computing Cloud?

Tim Bass Thu, 15 Nov 2007 23:55:07 +0000 *I predict we may experience less*debates*on the use of the term “event cloud”*related to*CEP in the future, now that both IBM and Google* have made announcements about “cloud computing” and “computing cloud”, IBM Turning Data Centers Into ‘Computing... (0 Replies)
Discussion started by: Linux Bot
0 Replies

2. Solaris

SunOS Popularity

Hey guys 3rd thred!!! :b: Anyways. I was looking into SunOS (Solaris/OpenSolaris) And i couldnt find anything about its popularity? Does this mean its not a very popular operating system? If not can you please post the link to your source. Thx -Megadrink :cool: (15 Replies)
Discussion started by: Megadrink
15 Replies

3. Solaris

boost thread not accessible to boost::move error

Hi All I am working unders Sun Solaris and I am not "/opt/boost/boost/thread/detail/thread.hpp", line 344: Error: boost::thread::thread(boost::thread&) is not accessible from boost::move(boost::detail::thread_move_t<boost::thread>). Do you know if there are other solutions other than... (2 Replies)
Discussion started by: manustone
2 Replies

4. Shell Programming and Scripting

Logical expression in POSIX compliant Korn Shell

Hi, i want to check if a variable var1 is not a or b or c pseudo code: If NOT (var1 = a or var1 = b or var1 = c) then ... fi I want to use POSIX complaint Korn shell, and for string comparison For the following code, logical.sh #!/usr/bin/ksh var="j" echo "Var : $var" if ! { || ||... (12 Replies)
Discussion started by: ysrini
12 Replies

5. Shell Programming and Scripting

Is Rule 7 of POSIX shell grammar rules written correctly?

The POSIX shell standard grammar rules are at Shell Command Language I am trying to understand Rule 7 and I don't. I think there may be some mistakes there. I am not complaining about the standard; rather, I am concerned that my perception is wrong, and I don't understand something important.... (3 Replies)
Discussion started by: Mark_Galeck
3 Replies

6. Shell Programming and Scripting

Pure POSIX shell scripting...

Hi all... This is more of a concensus question than help... As many of you know I am experimenting with the limitations of Pure POSIX shell scripting. Q: Is the directory /bin considered part of the Pure POSIX shell or must I stick entirely with the builtins only? The reason is I... (2 Replies)
Discussion started by: wisecracker
2 Replies

7. Shell Programming and Scripting

Equivalent to let command in POSIX shell

Hi all, I am learning POSIX shell programming, and the book I read, uses the let command for integer arithmetic. I have downloaded and use the shellcheck program on Linux. This programs says: In POSIX sh, 'let' is undefined. See the screenshot attached. What is the POSIX... (1 Reply)
Discussion started by: johnprogrammer
1 Replies

8. Shell Programming and Scripting

Q: Is SQRT(n) possible in a POSIX compliant shell? A: Yes within limits.

Hi all... This is just a fun project to see if it is possible to get a square root of a positive integer from 1 to 9200000 to 6 decimal places on a 64 bit architecture machine. It is coded around dash and the results show the values from 0 to 10000. Complex numbers can easily be catered for by... (3 Replies)
Discussion started by: wisecracker
3 Replies

9. OS X (Apple)

Generate a random number in a fully POSIX compliant shell, 'dash'...

Hi all... Apologies for any typos, etc... This took a while but it didn't beat me... Although there are many methods of generating random numbers in a POSIX shell this uses integer maths and a simple C source to create an executable to get epoch to microseconds accuracy if it is needed. I take... (8 Replies)
Discussion started by: wisecracker
8 Replies
CPANPLUS::Shell::Default::Plugins::HOWTO(3pm)		 Perl Programmers Reference Guide	     CPANPLUS::Shell::Default::Plugins::HOWTO(3pm)

NAME
CPANPLUS::Shell::Default::Plugins::HOWTO -- documentation on how to write your own plugins SYNOPSIS
package CPANPLUS::Shell::Default::Plugins::MyPlugin; ### return command => method mapping sub plugins { ( myplugin1 => 'mp1', myplugin2 => 'mp2' ) } ### method called when the command '/myplugin1' is issued sub mp1 { .... } ### method called when the command '/? myplugin1' is issued sub mp1_help { return "Help Text" } DESCRIPTION
This pod text explains how to write your own plugins for "CPANPLUS::Shell::Default". HOWTO
Registering Plugin Modules Plugins are detected by using "Module::Pluggable". Every module in the "CPANPLUS::Shell::Default::Plugins::*" namespace is considered a plugin, and is attempted to be loaded. Therefor, any plugin must be declared in that namespace, in a corresponding ".pm" file. Registering Plugin Commands To register any plugin commands, a list of key value pairs must be returned by a "plugins" method in your package. The keys are the commands you wish to register, the values are the methods in the plugin package you wish to have called when the command is issued. For example, a simple 'Hello, World!' plugin: package CPANPLUS::Shell::Default::Plugins::HW; sub plugins { return ( helloworld => 'hw' ) }; sub hw { print "Hello, world! " } When the user in the default shell now issues the "/helloworld" command, this command will be dispatched to the plugin, and its "hw" method will be called Registering Plugin Help To provide usage information for your plugin, the user of the default shell can type "/? PLUGIN_COMMAND". In that case, the function "PLUGIN_COMMAND_help" will be called in your plugin package. For example, extending the above example, when a user calls "/? helloworld", the function "hw_help" will be called, which might look like this: sub hw_help { " /helloworld # prints "Hello, world! " } If you dont provide a corresponding _help function to your commands, the default shell will handle it gracefully, but the user will be stuck without usage information on your commands, so it's considered undesirable to omit the help functions. Arguments to Plugin Commands Any plugin function will receive the following arguments when called, which are all positional: Classname -- The name of your plugin class Shell -- The CPANPLUS::Shell::Default object Backend -- The CPANPLUS::Backend object Command -- The command issued by the user Input -- The input string from the user Options -- A hashref of options provided by the user For example, the following command: /helloworld bob --nofoo --bar=2 joe Would yield the following arguments: sub hw { my $class = shift; # CPANPLUS::Shell::Default::Plugins::HW my $shell = shift; # CPANPLUS::Shell::Default object my $cb = shift; # CPANPLUS::Backend object my $cmd = shift; # 'helloworld' my $input = shift; # 'bob joe' my $opts = shift; # { foo => 0, bar => 2 } .... } BUG REPORTS
Please report bugs or other issues to <bug-cpanplus@rt.cpan.org<gt>. AUTHOR
This module by Jos Boumans <kane@cpan.org>. COPYRIGHT
The CPAN++ interface (of which this module is a part of) is copyright (c) 2001 - 2007, Jos Boumans <kane@cpan.org>. All rights reserved. This library is free software; you may redistribute and/or modify it under the same terms as Perl itself. SEE ALSO
CPANPLUS::Shell::Default, CPANPLUS::Shell, cpanp perl v5.12.5 2012-11-03 CPANPLUS::Shell::Default::Plugins::HOWTO(3pm)
All times are GMT -4. The time now is 04:19 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy